Base for pressurized bottles

ABSTRACT

A plastic bottle with a base centered on a vertical axis, a continuous standing ring to support the bottle, a side wall formed unitarily with the base extending from the base upward to an upper side wall end, and a neck connected to the side wall upper end, the neck including a finish adapted to receive a cap to close an opening into the bottle interior. The bottle base standing ring is defined in vertical cross-section by a continuous curve bounded on a radial inside by an interior region that can include a plurality of concave domed wedge-shaped sections interspaced with buttress sections having substantially planar inclined outer portions. The bottle base standing ring has a diameter less than 80% of the maximum side wall width and is bounded on a radial outside by a conic section portion centered on the vertical axis having an apex angle of less than 1600 to improve the perpendicularity of the bottle.

BACKGROUND

The present disclosure is directed to plastic bottles, and particularlyto a supporting champagne style base that is unitary with the remainderof the bottle, which improves the perpendicularity of the bottle.

Plastic bottles that include a base having a continuous uninterruptedstanding ring for supporting the bottle on any underlying surface aresometimes referred to having a champagne style base. Theperpendicularity or vertical alignment of such bottles can depend on theevenness of material distribution in the area of the standing ring,particularly when the bottles are subjected to even small internalpressures of 15 psi or less. While small variations from a true verticalalignment can be tolerated, any significant variation may cause problemsin subsequent labeling and boxing of such bottles. While a largediameter standing ring is generally thought to provide enhancedstability as a result of the larger foot print, the large diameterstanding ring is more flexible as a result of less material beingpresent in the standing ring. As a result, even small variations inmaterial distribution in large diameter standing rings can lead tounacceptable variations in the vertical alignment or perpendicularity ofthe bottle. This problem has in the past been addressed by forming apreform with significant non-uniform wall thicknesses so that asubstantial amount of material is placed in the chime in directalignment with the standing ring. Examples are to be found in U.S. Pat.Nos. 4,725,464; 4,780,257; 4,889,752 and 6,248,413.

A significant disadvantage of using preforms having significantnon-uniform wall thicknesses to place additional material in the chimein direct alignment with the standing ring is the additional polymeritself, which increases the cost of the bottle. There is thus a need fora lower-cost solution to enhance the perpendicularity or verticalalignment of blow molded plastic bottles having a champagne style base.

SUMMARY

A plastic bottle has a base centered on a vertical axis. The base has acontinuous standing ring to support the bottle on any underlying supportsurface. A side wall is formed unitarily with the base and extends fromthe base upward to an upper end of the side wall. A neck is unitarilyconnected to the upper end of the side wall that includes a finishadapted to receive a cap to close an opening into the bottle interior.The bottle has a height defined by the distance between the opening andthe standing ring, and a maximum width across the bottle. To enhance thevertical alignment or perpendicularity of the bottle, the base standingring can be defined in vertical cross-section by a continuous curve. Thebase standing ring can have a diameter less than 80% of the maximum sidewall width. The continuous curve of the base standing ring can bebounded on a radial inside by an interior region that includes aplurality of concave domed wedge-shaped sections interspaced withbuttress sections having substantially planar inclined outer portions.The continuous curve of the base standing ring can be bounded on aradial outside by a conic section portion centered on the vertical axis.

The vertical alignment or perpendicularity of the bottle can be enhancedby limiting the apex angle of the conic section portion to less than160°. The vertical alignment or perpendicularity of the bottle can befurther enhanced by maintaining the width of the conic section portionto at least 0.035 inches (0.889 cm).

The vertical alignment or perpendicularity of the bottle can also beenhanced by limiting the standing ring diameter to be more than 70% ofthe maximum bottle side wall width. The vertical alignment orperpendicularity of the bottle can be further enhanced by limiting theaverage standing ring thickness to between 1.0 and 1.3 times thethickness of the side wall. The vertical alignment or perpendicularityof the bottle can be further enhanced by limiting variation in thestanding ring thickness to less than ±20%. Another feature of the basethat can improve the vertical alignment or perpendicularity of thebottle is confining the vertical cross-sectional radius defining thestanding ring to between 0.100 inches (0.254 cm) and 0.300 inches (0.762cm).

Another feature of the base that can improve the vertical alignment orperpendicularity of the bottle is limiting the curvature of the concavedome portion to a radius of at least 1.0 times the standing ringdiameter. The vertical alignment or perpendicularity of the bottle canbe further enhanced by buttress sections that have inclined outerportions that can be inclined at an angle of between 8° and 16° withrespect to a plane defined by the base standing ring. The verticalalignment or perpendicularity of the bottle can be further enhanced byproviding the angle of tangency at the point of intersection of theconcave dome portion and the standing ring vertical cross-section to beat least 45°.

Other features of the present bottle base and the correspondingadvantages of those features will become apparent from the followingdiscussion of the preferred embodiments of the present container,exemplifying the best mode of practice, which is illustrated in theaccompanying drawings. The components in the figures are not necessarilyto scale, emphasis instead being placed upon illustrating the principlesof the features. Moreover, in the figures, like referenced numeralsdesignate corresponding parts throughout the different views.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional outline of an exterior surface of a bottle.

FIG. 2 is a bottom plan view of the base of the bottle in FIG. 1.

FIG. 3 is a sectional outline view of the base taken along line 3-3 ofFIG. 2.

FIG. 4 is an enlarged view of a portion of the left side of FIG. 3.

FIG. 5 is an enlarged view of a portion of the right side of FIG. 3.

DESCRIPTION OF A PREFERRED EMBODIMENT

A bottle 10 is shown in FIG. 1 and the other Figs that has a generallycylindrical body 12 surrounding a longitudinal axis Y and a closed base14 that is unitary with the remainder of the bottle. The 14 base has acontinuous standing ring 16 to support the bottle 10 on any underlyingsupport surface. The standing ring 16 has a standing ring diameter D. Aside wall 18 is formed unitarily with the base 14 and extends from thebase upward to an upper end 20 of the side wall 18. A neck 22 isunitarily connected to the upper end 20 of the side wall 18 by ashoulder portion 21. The neck 22 includes a finish 24 adapted to receivea cap (not shown) to close an opening 26 into the bottle interior 28.The bottle 10 has a height H defined by the distance between the opening26 and the standing ring 16, and a maximum width W across the bottle 10.

To enhance the vertical alignment or perpendicularity of the bottle 10,the base standing ring 16 can be defined in vertical cross-section by acontinuous curve of radius R_(S), shown in FIGS. 4 and 5, which can bebetween 0.100 inches (0.254 cm) and 0.300 inches (0.762 cm). The radiusR_(S) is independent of the standing ring diameter D, where the standingring diameter D is measured at the lowest point on the standing ring 16.The curve defining the standing ring 16, being continuous, does notinclude any flattened portion in the plane X defined by the standingring, shown in FIG. 3. The base standing ring 16 can have a diameter Dless than 80% of the maximum side wall width W. The base standing ring16 can have a diameter D greater than 70% of the maximum side wall widthW.

The continuous curve of the base standing ring 16 defined by R_(S) canbe bounded on a radial inside, starting about at point or ring 30, by aninterior region 32. The interior region 32 can include a plurality ofconcave domed wedge-shaped sections 34 as seen in FIG. 2. The concavedomed wedge-shaped sections 34 can be formed by a constant inside radiusR_(C) of at least 1.0 times the standing ring diameter D as shown inFIGS. 3 and 5. The angle of tangency λ at the point of intersection 30of the concave dome portions 34 and the curve defining the standing ring16 measured from the plane X as shown in FIG. 5 can be between 45°and55°. The wedge-shaped sections 34 can be interspaced with buttresssections 36, which can also be wedge-shaped. The buttress sections 36can have substantially planar inclined outer portions 38. The planarouter portions 38 can be inclined at an angle θ of between 8° and 16°with respect to a plane X defined by the base standing ring 16 as seenin FIG. 4. The buttress sections 36 can include inner portions 40defined by a concave surface 42 that becomes circumferentiallycontinuous as it approaches a central downwardly protruding portion 44surrounding the axis Y of the bottle. The lowest surface of thedownwardly protruding portion 44 can be spaced above the plane X by adistance H_(C) of 14% to 20% of the standing ring diameter D.

The continuous curve of the base standing ring 16 defined by radiusR_(S) can be bounded on a radial outside by a conic section portion 46starting at point or ring 48 and extending linearly upwardly andoutwardly to point or ring 50 as shown in FIGS. 4 and 5. The distancebetween point or ring 48 and point or ring 50 defines the width of theconic section portion 46, which is preferably at least 0.035 inches(0.089 cm). The conic section portion 46 is seen to be generated by therotation around the vertical axis Y of a line generating a conic sectionhaving an included apex angle Φ of less than 160° as shown in FIG. 3. Abase outer portion 52 extending outward from point 50 to the side wall18 can be formed as a torus segment defined by a constant radius R_(T)of between about 12% and 20% of the standing ring diameter D.

Between the point or ring 30 and the point or ring 48, the materialforming the standing ring 16 preferably has an average thickness ofbetween 1.0 and 1.3 times the thickness of the material forming the sidewall 18. Between the point or ring 30 and the point or ring 48, thethickness of the material forming the standing ring 16 desirably has avariation that is as small as possible and less than ±20%.

By way of example, a bottle 10 as shown in FIG. 1 can have a height H of8.813 inches (22.39 cm) and a maximum width W of 2.52 inches (6.40 cm).The standing ring diameter D of the example bottle can be 1.90 inches(4.826 cm). The vertical cross-section radius R_(S) defining theexterior surface of the standing ring 16 of the example bottle can be0.150 inches (0.381 cm). The width of the conic section portion 46 ofthe example bottle can be 0.064 inches (0.163 cm). The average thicknessof the material forming the side wall 16 of the example bottle can be0.014 inches (0.0356 cm) while the average thickness of the materialforming the standing ring can be 0.016 inches (0.0406 cm). The insideradius R_(C) forming the concave surfaces of the domed wedge-shapedsections 34 of the example bottle can be 1.990 inches (5.055 cm). Theangle of tangency λ at the point of intersection 30 of the concave domeportions 34 and the curve defining the standing ring 16 measured fromthe plane X in the example bottle can be 50°. The angle of inclination θof the planar outer portions 38 of the buttress sections 36 of theexample bottle can be 11°. The radius R_(C) defining the concave surface40 of the example bottle can be 0.263 inches (0.668 cm). The lowestsurface of the central downwardly protruding portion 44 of the examplebottle can be spaced above the plane X by a distance of 0.315 inches(0.800 cm). The apex angle Φ of the conic section generating the portion46 of the example bottle can be 150°. The radius R_(T) forming the baseouter portion 52 of the example bottle can be 0.300 inches (0.762 cm).The example bottle showed a 36% improvement in perpendicularity over aprior design.

While these features have been disclosed in connection with theillustrated preferred embodiment, other embodiments of the inventionwill be apparent to those skilled in the art that come within the spiritof the invention as defined in the following claims.

1. A plastic bottle comprising a base centered on a vertical axis, thebase having a standing ring to support the bottle on any underlyingsupport surface, a side wall formed unitarily with the base andextending from the base upward to an upper end of the side wall, and aneck connected to the upper end of the side wall, the neck including afinish adapted to receive a cap to close an opening into the bottleinterior, the bottle having a height defined by the distance between theopening and the standing ring, and a maximum width across the side wall,the base standing ring being defined in vertical cross-section by acontinuous curve, the continuous curve being bounded on a radial insideby an interior region, the continuous curve being bounded on a radialoutside by a conic section portion centered on the vertical axis, thebase standing ring having a diameter less than 80% of the maximum sidewall width.
 2. The plastic bottle of claim 1, wherein the conic sectionportion has an apex angle of less than 160°.
 3. The plastic bottle ofclaim 1, wherein the base standing ring diameter is more than 70% of themaximum side wall width.
 4. The plastic bottle of claim 1, wherein thestanding ring has an average thickness that is between 1.0 and 1.3 timesthe average thickness of the side wall.
 5. The plastic bottle of claim4, wherein the variation in standing ring thickness is less than ±20%.6. The plastic bottle of claim 1, wherein the continuous curve of thestanding ring has a defining radius in vertical cross-section of between0.100 inches and 0.300 inches.
 7. The plastic bottle of claim 1, whereinthe interior region comprises a plurality of concave domed wedge-shapedsections interspaced with buttress sections having substantially planarinclined outer portions.
 8. The plastic bottle of claim 7, wherein theconcave dome portion is defined by a curve having a radius of at least1.0 times the standing ring diameter.
 9. The plastic bottle of claim 7,wherein the planar inclined outer portions of the buttress sections areinclined at an angle of between 8° and 16° with respect to a planedefined by the base standing ring.
 10. The plastic bottle of claim 7,wherein the angle of tangency at the point of intersection of theconcave dome portion and the curve defining the standing ring measuredfrom the plane defined by the standing ring is between 45° and 55°. 11.A plastic bottle comprising a base centered on a vertical axis, the basehaving a continuous circular standing ring to support the bottle on anyunderlying support surface, a cylindrical side wall formed unitarilywith the base and extending from the base upward to an upper end of theside wall, and a neck connected to the upper end of the side wall, theneck including a finish adapted to receive a cap to close an openinginto the bottle interior, the bottle having a height defined by thedistance between the opening and the standing ring, and a maximumdiameter across the side wall, the base standing ring being defined invertical cross-section by a continuous curve of constant radius having adiameter of between 70% and 80% of the maximum side wall diameter, thecontinuous curve of the standing ring being bounded on a radial insideby an interior region, the continuous curve of the standing ring beingbounded on a radial outside by a constant angle tapered portion definedby a conic section centered on the vertical axis having an apex angle ofless than 160°.
 12. The plastic bottle of claim 11, wherein the standingring has an average thickness that is between 1.0 and 1.3 times theaverage thickness of the side wall and the variation in standing ringthickness is less than ±20%.
 13. The plastic bottle of claim 11, whereinthe continuous curve of the standing ring has a defining radius invertical cross-section of between 0.100 inches and 0.300 inches.
 14. Theplastic bottle of claim 11, wherein the interior region comprises aconcave domed shaped portion.
 15. The plastic bottle of claim 14,wherein the concave domed shaped portion includes a plurality of concavedomed wedge-shaped sections interspaced with buttress sections havingsubstantially planar inclined outer portions.
 16. The plastic bottle ofclaim 15, wherein the buttress sections planar inclined outer portionsare inclined at an angle of between 8° and 16° with respect to a planedefined by the base standing ring.
 17. The plastic bottle of claim 14,wherein the concave dome portion is defined by a curve having a radiusof at least 1.0 times the standing ring diameter.
 18. The plastic bottleof claim 14, wherein the angle of tangency at the point of intersectionof the concave dome portion and the curve defining the standing ringmeasured from the plane defined by the standing ring is between 45°and55°.
 19. The plastic bottle of claim 11, wherein the constant angletapered portion outside the base standing ring has a width of between0.035 inches and 0.095 inches.
 20. A plastic bottle comprising a basecentered on a vertical axis, the base having a continuous circularstanding ring to support the bottle on any underlying support surface, acylindrical side wall formed unitarily with the base and extending fromthe base upward to an upper end of the side wall, and a neck connectedto the upper end of the side wall, the neck including a finish adaptedto receive a cap to close an opening into the bottle interior, thebottle having a height defined by the distance between the opening andthe standing ring, and a maximum diameter across the side wall, the basestanding ring having a diameter of between 70% and 80% of the maximumside wall diameter, the base standing ring being defined in verticalcross-section by a continuous curve of constant radius of between 0.100inches and 0.300 inches, the continuous curve of the standing ring beingbounded on a radial inside by an interior region that includes aplurality of concave domed wedge-shaped sections defined by a curvehaving a radius of at least 1.0 times the standing ring diameter, theconcave domed wedge-shaped sections intersecting the continuous curve ofthe standing ring at an angle of tangency measured from a plane definedby the base standing ring of between 45° and 55°, the plurality ofconcave domed wedge-shaped sections being interspaced with wedge-shapedbuttress sections having substantially planar outer portions inclined atan angle of between 8° and 16° with respect to the plane defined by thebase standing ring, the continuous curve of the standing ring beingbounded on a radial outside by a constant angle tapered portion definedby a conic section centered on the vertical axis having an apex angle ofless than 160° and having a width of between 0.035 inches and 0.095inches.